Battery Spaghetti Fix - Bus Bars

I used to think bus bars were often for those obsessed with neatness and unnecessary for just a few connections. However, after adding solar power, a battery monitor and a charger to our electrical system, our battery now looks like this..I expect this tangle of wires with no less than 3 fuses attached will make things a bit unwieldy when it comes to battery maintenance & cleaning. Plus, there are a couple more negative post connections already moved to the monitor shunt in addition to these.

Our tub has gotten quite full with all the additions, so this is the only space left..There is already a similar junction box holding the shunt wiring for the battery monitor, which I plan to reposition a bit to the left to make room for a second box..I plan to use some metal brackets to hang them as shown by this digital clone, the only way I could find to fit them both close to the battery box. I'll try to fit the fuses inside the box too.

Finally, here is my wiring plan showing how all three components will be rewired.I drew in the new wire connections at the bus bars, each keyed to a number label on the existing old connection locations..The blue connector (4) on the battery pos terminal is the battery temp sensor/shunt power lead, which will remain on the battery, the only other battery connection besides the two 6G black & red cables from the shunt/buss bar boxes.(for size reference, I put a 6" white ruler inside the bus bar box, but the 3 photos in this composite are not shown at the same scale)

I may not actually get this project done until after warmer weather has returned, when those wires will not be so stiff & easier to reroute. Please let me know if you see any issues with this setup, as I have plenty of time to make changes.

Yes, @MuttonChops, that is true, it might be a bit less convenient to get at the fuses - one bolt to loosen plus two screws in the top of the junction box. On the other hand, I've never needed to check any of these fuses, and I don't think I'd need to do it quickly. I figure it's a small price for having them well protected from corrosive dirt & water. Mounting on the diamond plate sounds like it might be more convenient for fuse access, but I don't think I have enough space available. Will have to look again. It might also require extending or replacing some cables. Thanks for that idea.

An unseasonably mild 60° day yesterday made wires more flexible & gave me the opportunity to complete this project..

Unfortunately, I could not find any other place to mount the junction box holding the bus bars, as @MuttonChops had suggested. Since this new box is a bit larger than the one holding the monitor shunt, I had to mount it at an angle to fit it in.

The shunt box no longer has a bunch of battery negative wires connected to the load side (bottom terminal) of the shunt; as these have been moved to the negative bus bar in the newly added junction box, and replaced by a new 6G cable to that bus bar.

This new junction box holds all the (+) and (-) cables previously connected to the battery, including the three labeled fuses. I took this photo before replacing the two plastic protective caps that snap over the two rows of bus bar terminals.

With regard to the issue @MuttonChops raised about having to unscrew the box top to access fuses, I realized that both the charger & solar lines have pigtail ends hanging inside the tub, so I could easily check the integrity of both fuses simultaneously without opening the box, by connecting a multimeter to their positive ends & performing a continuity test. If it failed, then at least one of the fuses may be bad.Not sure if there is an equivalent shortcut for the trailer fuse, though I would expect there would normally be a higher index of suspicion involved with the need to check that trailer line fuse (if one needs to check it, then it is likely bad?).

So, here's the difference the new junction box with bus bars makes at the battery.

It would have been just the two big cables remaining, except the battery monitor has a battery temperature sensor (blue connector) at the positive terminal, a line which also powers the monitor. This will make battery maintenance & clean up a whole lot easier & with less exposure of fuses to corrosion.

Forgot this one..Final test of wiring showing two cell phone displays of the battery monitor app connection via wireless bluetooth connection with house power off, then on. Everything appears to be working normally. Without AC power hookup, the monitor display at left correctly shows a fully charged voltage with a negative 200 milliamp current consumption from background trailer electronics that would drain the battery in about 10 days at 57°F. With power reconnected, the typical converter float charge voltage of 13.6V & 1 amp positive charge current is displayed. This will typically drop back to a 13.2V trickle charge after 2-3 days..

Thanks, @jkjenn, I may have never gotten this far along without first following your lead to get the Victron monitor & SCC. I've been very happy with both. I sometimes wonder how we got along without the battery monitor, and when using solar it's a thing of beauty to see how it works together with the SCC to keep the battery charged & let you know its status & usage history. And now that our [email protected] is covered for the winter, I can check the battery status remotely from the app without even going outside. So thank you!

"With regard to the issue @MuttonChops raised about having to unscrew the box top to access fuses, I realized that both the charger & solar lines have pigtail ends hanging inside the tub, so I could easily check the integrity of both fuses simultaneously without opening the box, by connecting a multimeter to their positive ends & performing a continuity test. If it failed, then at least one of the fuses may be bad.Not sure if there is an equivalent shortcut for the trailer fuse,"

Yes, I believe there is, but please correct me if I'm wrong!..

Battery switch must be on, then..To check the trailer fuse inside the bus bar box without opening it, perform another continuity test by connecting one probe to one of the same pigtails connected to the positive bus bar. Then, connect the other test probe to the 12V positive connector inside the trailer's 7-way plug (top left terminal socket in the plug). If it beeps positive, then both fuses on those lines inside the bus bar box are good.So, no need to open the box to check any of the fuses, and a continuity test is better than a visual inspection anyway!